Make socket exceptions more specific to match Python semantics

include/ZeroTierSockets.h

@@ -200,7 +200,7 @@ typedef enum {
 extern int zts_errno;
 
 typedef enum {
-    /** Operation not permitted (`zts_errno` value) */
+    /** Operation not permitted */
     ZTS_EPERM = 1,
     /** No such file or directory */
     ZTS_ENOENT = 2,
@@ -278,6 +278,8 @@ typedef enum {
     ZTS_ENOTCONN = 107,
     /** Connection timed out */
     ZTS_ETIMEDOUT = 110,
+    /* Connection refused */
+    ZTS_ECONNREFUSED = 111,
     /** No route to host */
     ZTS_EHOSTUNREACH = 113,
     /** Operation already in progress */

src/bindings/python/libzt.py

@@ -158,6 +158,7 @@ ZTS_ENOBUFS = _libzt.ZTS_ENOBUFS
 ZTS_EISCONN = _libzt.ZTS_EISCONN
 ZTS_ENOTCONN = _libzt.ZTS_ENOTCONN
 ZTS_ETIMEDOUT = _libzt.ZTS_ETIMEDOUT
+ZTS_ECONNREFUSED = _libzt.ZTS_ECONNREFUSED
 ZTS_EHOSTUNREACH = _libzt.ZTS_EHOSTUNREACH
 ZTS_EALREADY = _libzt.ZTS_EALREADY
 ZTS_EINPROGRESS = _libzt.ZTS_EINPROGRESS

src/bindings/python/sockets.py

@@ -6,6 +6,27 @@ import libzt
 def handle_error(err):
     """Convert libzt error code to exception"""
     if err == libzt.ZTS_ERR_SOCKET:
+        if errno() == libzt.ZTS_EAGAIN:
+            raise BlockingIOError()
+            return
+        if errno() == libzt.ZTS_EINPROGRESS:
+            raise BlockingIOError()
+            return
+        if errno() == libzt.ZTS_EALREADY:
+            raise BlockingIOError()
+            return
+        if errno() == libzt.ZTS_ECONNABORTED:
+            raise ConnectionAbortedError()
+            return
+        if errno() == libzt.ZTS_ECONNREFUSED:
+            raise ConnectionRefusedError()
+            return
+        if errno() == libzt.ZTS_ECONNRESET:
+            raise ConnectionResetError()
+            return
+        if errno() == libzt.ZTS_ETIMEDOUT:
+            raise TimeoutError()
+            return
         raise Exception("ZTS_ERR_SOCKET (" + str(err) + ")")
     if err == libzt.ZTS_ERR_SERVICE:
         raise Exception("ZTS_ERR_SERVICE (" + str(err) + ")")